Calcium/phosphate ratio: an additional tool for the clinical management of asymptomatic primary hyperparathyroidism?

PURPOSE: Serum calcium/phosphate ratio (Ca/P) has been recently proposed as an additional tool to identify primary hyperparathyroidism (PHPT), especially in patients with subclinical presentation, with a proposed cut-off of 3.3 when both values are expressed in mg/dL. No data are available on the relationship between Ca/P and the clinical presentation of PHPT. We thus evaluated this relationship in a large, single-center, unselected series. METHODS: 515 consecutive PHPT patients (mean age 65 ± 13.15 years, 77.1% females) were retrospectively evaluated at diagnosis. RESULTS: Mean Ca/P was 4.54 ± 1.5 (range 2.36-13.9), being higher than 3.3 in 88.5% of patients. Ca/P was significantly higher in (1) males, (2) symptomatic PHPT, (3) patients with 25-hydroxy vitamin D levels lower than 20 µg/L, (4) patients with osteitis fibrosa cystica, (5) patients with T score < - 2.5 at the radial site. In a multivariate regression analysis, Ca/P resulted significantly associated with PTH levels. After the exclusion of 57 patients with asymptomatic PHPT (aPHPT) patients and serum Ca higher than 1 mg/dL above the upper limit of normal range, no differences were found in Ca/P between aPHPT meeting or not surgical criteria. CONCLUSIONS: In PHPT Ca/P ratio is associated with increased biochemical and clinical severity of disease and represents a direct indicator of clinical bone damage. However, it does not seem an additional tool to identify aPHPT patients reaching surgical indication.

Italian guidelines for the management of adult individuals with overweight and obesity and metabolic comorbidities that are resistant to behavioral treatment.

AIM: This guideline (GL) is aimed at providing a clinical practice reference for the management of adult patients with overweight or obesity associated with metabolic complications who are resistant to lifestyle modification. METHODS: Surgeons, endocrinologists, gastroenterologists, psychologists, pharmacologists, a general practitioner, a nutritionist, a nurse and a patients' representative acted as multi-disciplinary panel. This GL has been developed following the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. A systematic review and network meta-analysis was performed by a methodologic group. For each question, the panel identified potentially relevant outcomes, which were then rated for their impact on therapeutic choices. Only outcomes classified as "critical" and "important" were considered in the systematic review of evidence. Those classified as "critical" were considered for clinical practice recommendations. Consensus on the direction (for or against) and strength (strong or conditional) of recommendations was reached through a majority vote. RESULTS: The present GL provides recommendations about the role of both pharmacological and surgical treatment for the clinical management of the adult patient population with BMI > 27 kg/m2 and < 40 kg/m2 associated with weight-related metabolic comorbidities, resistant to lifestyle changes. The panel: suggests the timely implementation of therapeutic interventions in addition to diet and physical activity; recommends the use of semaglutide 2.4 mg/week and suggests liraglutide 3 mg/day in patients with obesity or overweight also affected by diabetes or pre-diabetes; recommends semaglutide 2.4 mg/week in patients with obesity or overweight also affected by non-alcoholic fatty liver disease; recommends semaglutide 2.4 mg/week as first-line drug in patients with obesity or overweight that require a larger weight loss to reduce comorbidities; suggests the use of orlistat in patients with obesity or overweight also affected by hypertriglyceridemia that assume high-calorie and high-fat diet; suggests the use of naltrexone/bupropion combination in patients with obesity or overweight, with emotional eating; recommends surgical intervention (sleeve gastrectomy, Roux-en-Y gastric bypass, or metabolic gastric bypass/gastric bypass with single anastomosis/gastric mini bypass in patients with BMI ≥ 35 kg/m2 who are suitable for metabolic surgery; and suggests gastric banding as a possible, though less effective, surgical alternative. CONCLUSION: The present GL is directed to all physicians addressing people with obesity-working in hospitals, territorial services or private practice-and to general practitioners and patients. The recommendations should also consider the patient's preferences and the available resources and expertise.

Treatment of Obesity with Thyroid hormones in Europe. Data from the THESIS* Collaboration.

PURPOSE: The use of thyroid hormones (TH) to treat obesity is unsupported by evidence as reflected in international guidelines. We explored views about this practice, and associations with respondent characteristics among European thyroid specialists. METHODS: Specialists from 28 countries were invited to a survey via professional organisations. The relevant question was whether "Thyroid hormones may be indicated in biochemically euthyroid patients with obesity resistant to lifestyle interventions". RESULTS: Of 17,232 invitations 5695 responses were received (33% valid response rate; 65% women; 90% endocrinologists). Of these, 290 (5.1%) stated that TH may be indicated as treatment for obesity in euthyroid patients. This view was commoner among non-endocrinologists (8.7% vs. 4.7%, p < 0.01), private practice (6.5% vs. 4.5%, p < 0.01), and varied geographically (Eastern Europe, 7.3%; Southern Europe, 4.8%; Western Europe, 2.7%; and Northern Europe, 2.5%). Respondents from Northern and Western Europe were less likely to use TH than those from Eastern Europe (p < 0.01). Gross national income (GNI) correlated inversely with this view (OR 0.97, CI: 0.96-0.97; p < 0.001). Having national guidelines on hypothyroidism correlated negatively with treating obesity with TH (OR 0.71, CI: 0.55-0.91). CONCLUSIONS: Despite the lack of evidence, and contrary to guidelines' recommendations, about 5% of respondents stated that TH may be indicated as a treatment for obesity in euthyroid patients resistant to life-style interventions. This opinion was associated with (i) respondent characteristics: being non-endocrinologist, working in private practice, treating a small number of hypothyroid patients annually and (ii) national characteristics: prevalence of obesity, Eastern Europe, low GNI and lack of national hypothyroidism guidelines.

Use of thyroid hormones in hypothyroid and euthyroid patients: A 2020 THESIS questionnaire survey of members of the Danish Endocrine Society.

PURPOSE: The standard treatment of hypothyroidism is levothyroxine (LT4), which is available as tablets or soft-gel capsules in Denmark. This study aimed to investigate Danish endocrinologists' use of thyroid hormones in hypothyroid and euthyroid patients. METHODS: An e-mail with an invitation to participate in an online survey investigating practices about substitution with thyroid hormones was sent to all members of the Danish Endocrine Society (DES). RESULTS: Out of 488 eligible DES members, a total of 152 (31.2%) respondents were included in the analysis. The majority (94.1%) of responding DES members use LT4 as the treatment of choice. Other treatment options for hypothyroidism are also used, as 58.6% prescribe combination therapy with liothyronine (LT3) + LT4 in their clinical practice. LT4 + LT3 combination is preferred in patients with persistent symptoms of hypothyroidism despite biochemical euthyroidism on LT4 treatment. Over half of the respondents answered that thyroid hormone therapy is never indicated for euthyroid patients, but 42.1% will consider it for euthyroid infertile women with high antibody levels. In various conditions that could interfere with the absorption of LT4, most responding Danish endocrinologists prefer tablets and do not expect a significant difference when switching from one type of tablet formulation to another. CONCLUSION: The treatment of choice for hypothyroidism is LT4. Combination therapy with LT4 + LT3 is considered for patients with persistent symptoms. Even in the presence of conditions affecting bioavailability, responding Danish endocrinologists prefer LT4 tablets rather than newer LT4 formulations, such as soft-gel capsules.

Use of Thyroid Hormones in Hypothyroid and Euthyroid Patients: A Thesis* Questionnaire Survey of Romanian Physicians *Thesis: Treatment of Hypothyroidism in Europe by Specialists: an International Survey.

OBJECTIVE: Romania has no national guidelines for hypothyroidism treatment, nor are there any recommendations from national societies to adhere to international guidelines. Our aim was to identify the attitudes of Romanian physicians relating to hypothyroidism treatment focusing on available formulations of levothyroxine (LT4). METHODS: All 748 members of the Romanian Society of Endocrinology were invited to participate in a web-based survey. A total of 316 (42.24%) members responded, of whom 222 (70.2%) completed all questions. RESULTS: Half of the respondents recommended LT4 treatment in euthyroid patients, from 3.6% in euthyroid patients with obesity to 36.4% in euthyroid females with infertility associated with high levels of thyroid antibodies. LT4 was considered the preferred treatment for hypothyroidism (compared to combination treatment of LT4 with LT3 or LT3 alone) by 98.6% of respondents. LT4 in liquid solution was preferred over tablets if malabsorption is suspected (56.5% vs. 27.3%), for patients with unexplained poor biochemical control (52.5% vs. 22.9%) and for patients not able to adhere to ingesting LT4 fasted (74.0% vs. 9.8%). The most and least probable explanations for persistent symptoms in patients with hypothyroidism who achieve a normal TSH under medication were "psychosocial factors" and "burden of having to take medication", respectively. CONCLUSION: A significant proportion of Romanian physicians would use LT4 in some groups of euthyroid patients, contrary to current evidence. The preferred treatment for hypothyroidism was LT4. Alternative LT4 formulations (liquid solution) are considered in specific clinical conditions. Diversification of available thyroid hormone formulations was readily incorporated into everyday practice.

Mild primary hyperparathyroidism as defined in the Italian Society of Endocrinology's Consensus Statement: prevalence and clinical features.

BACKGROUND: Mild primary hyperparathyroidism (PHPT) was recently clearly defined for the first time. Our study was thus aimed to pinpoint proportion and clinical characteristics of this kind of patients. DESIGN AND PATIENTS: We retrospectively evaluated our series of 360 consecutive patients with PHPT, selecting those with all features allowing a correct classification (serum total and ionized calcium, phosphate, creatinine, PTH, 25OHD, urinary calcium, renal and neck ultrasound, MIBI scintiscan, and DEXA at lumbar spine, femoral neck, and distal third of radius). Patients were defined asymptomatic (aPHPT) when bone or kidney was not involved and no hypercalcemic symptom occurred; mild PHPT was defined as aPHPT not meeting updated surgical criteria. RESULTS: Seventy-five patients among 172 classified as aPHPT had all available data required for surgical evaluation and could be evaluated. Sixty/75 met surgical criteria and the remaining 15 were classified as mild. Mild PHPT patients had lower total and ionized calcium, urinary calcium, and PTH levels than aPHPT meeting surgical criteria, while vitamin D levels and BMD were similar. CONCLUSIONS: Mild PHPT strictly defined according to the last consensus represents a small subgroup with a less active form of the disease.

Italian association of clinical endocrinologists (AME) position statement: drug therapy of osteoporosis.

Treatment of osteoporosis is aimed to prevent fragility fractures and to stabilize or increase bone mineral density. Several drugs with different efficacy and safety profiles are available. The long-term therapeutic strategy should be planned, and the initial treatment should be selected according to the individual site-specific fracture risk and the need to give the maximal protection when the fracture risk is highest (i.e. in the late life). The present consensus focused on the strategies for the treatment of postmenopausal osteoporosis taking into consideration all the drugs available for this purpose. A short revision of the literature about treatment of secondary osteoporosis due both to androgen deprivation therapy for prostate cancer and to aromatase inhibitors for breast cancer was also performed. Also premenopausal females and males with osteoporosis are frequently seen in endocrine settings. Finally particular attention was paid to the tailoring of treatment as well as to its duration.

Growth hormone treatment of adolescents with growth hormone deficiency (GHD) during the transition period: results of a survey among adult and paediatric endocrinologists from Italy. Endorsed by SIEDP/ISPED, AME, SIE, SIMA.

Treatment of adolescents with growth hormone deficiency (GHD) during the transition period is a controversial issue. This paper is a contribution from the Italian community of paediatric and adult endocrinologists surveyed in a Delphi panel. The Delphi method is a structured communication technique, originally developed as a systematic, interactive forecasting method that relies on a panel of experts. The experts answer questionnaires in two or more rounds. There was substantial agreement on the definition of the problems associated with the diagnosis and treatment of adolescents with GHD in the transition period, as well as on the identification of the controversial issues which need further studies. There is general consensus on the need of re-testing all isolated idiopathic GHD after at least 30-day withdrawn from treatment, while in patients with multiple pituitary deficiency and low IGF-I levels there is generally no need to re-test. In patients with permanent or confirmed GHD, a starting low rhGH dose (0.01-0.03 mg per day) to be adjusted according to IGF-I concentrations is also widely accepted. For those continuing treatment, the optimal therapeutic schedule to obtain full somatic maturation, normalization of body composition and bone density, cardiovascular function and Quality of Life, need to be evaluated.

Decreased adrenergic tone in acromegaly: evidence from direct recording of muscle sympathetic nerve activity.

OBJECTIVE: Sympathovagal imbalance has been shown in acromegaly by indirect measurements of adrenergic tone. Data regarding direct measurement of sympathetic activity are lacking as yet. Aim of this study was to assess the adrenergic tone through direct recording of muscle sympathetic nerve activity (MSNA) in acromegalic patients. DESIGN: Fifteen patients (age 26-66 years, eight women) with newly diagnosed active acromegaly without hyperprolactinaemia, pituitary hormone deficiencies, obstructive sleep apnoea and cardiac hypertrophy, and 15 healthy subjects matched for age, sex and body mass index were recruited. After evaluating anthropometric and echocardiographic parameters, anterior pituitary function, glucose and lipid metabolism, and measuring plasma leptin, direct recording of sympathetic outflow via the microneurographic technique was performed. RESULTS: For similar anthropometric and metabolic parameters in patients and controls, HOMA index was significantly increased in the former (4·2 ± 2·39 vs 1·6 ± 0·19, P < 0·001). Surprisingly, this finding of insulin resistance was accompanied by a marked sympathetic inhibition (MSNA 18·3 ± 8·10 vs 37·3 ± 6·48 bursts/min, P < 0·0001, respectively in patients and controls). A reduction in plasma leptin (1·6 ± 1·04 vs 6·5 ± 2·01 µg/l, P < 0·0001) was also recorded in the patients. MSNA was positively correlated with leptin (P < 0·0001). CONCLUSIONS: Newly diagnosed acromegalic patients without cardiac hypertrophy display a decreased sympathetic outflow in spite of insulin resistance. This finding might be related to hypoleptinaemia.

[Features of the use of synthetic analogues of thyroid hormones: а 2020 THESIS* questionnaire survey of members of the Belarusian Public Medical Association of Endocrinology and Metabolism].

BACKGROUND: The standard treatment for hypothyroidism is levothyroxine (LT4), which in the Republic of Belarus is available in tablet form whereas liothyronine (LT3) is not registered, but patients can purchase them on their own abroad. AIM: This study aimed to investigate Belarusian endocrinologists' attitude of thyroid hormones in hypothyroid and euthyroid patients. MATERIALS AND METHODS: An online survey was conducted, for which members of the Belarusian Medical Association of Endocrinology and Metabolism were invited by posting information in the group chat and by e-mail. The research period was from October 1 to December 26, 2020. 210 questionnaires were received, 146 of which were used. RESULTS: The majority of participants, 145 (99.3%), indicated that they were using LT4 as the first-choice drug for the treatment hypothyroidism. Sixty-one (41.8%) doctors answered that LT3 + LT4 combination likely can be used in patients with long-term untreated hypothyroidism and 15 (10.3%) - in patients with persistent symptoms of hypothyroidism, despite biochemical euthyroidism on therapy LT4. Over half of the respondents 84 (57.5%) answered that thyroid hormone therapy was never indicated for euthyroid patients, but 50 (34.2%) would consider it for female infertility with high level of thyroid antibodies and 36 (24.7%) for simple goiter growing over time. In various conditions that could interfere with absorption of LT4, most responding Belarusian endocrinologists do not expect a significant difference with different formulations (tablets+"I do not expect major changes in different forms" vs. "soft gel capsules"+"liquid solution"; p <0.001). Persistent symptoms of hypothyroidism on the background of LT4 replacement therapy with the achievement of the target TSH can mainly be caused by psychosocial factors, concomitant diseases, unrealistic patient expectations, chronic fatigue syndrome, and the burden of chronic disease. CONCLUSION: The method of choice of Belarusian endocrinologists in the treatment of hypothyroidism is LT4 replacement therapy, but the appointment of LT4 + LT3 combination therapy can be considered in certain clinical situations. As a rule, endocrinologists do not prescribe LT4 in patients with euthyroidism and do not expect a significant difference when using other forms of levothyroxine.

Novel OTOF mutations in Brazilian patients with auditory neuropathy.

The OTOF gene encoding otoferlin is associated with auditory neuropathy (AN), a type of non-syndromic deafness. We investigated the contribution of OTOF mutations to AN and to non-syndromic recessive deafness in Brazil. A test for the Q829X mutation was carried out on a sample of 342 unrelated individuals with non-syndromic hearing loss, but none presented this mutation. We selected 48 cases suggestive of autosomal recessive inheritance, plus four familial and seven isolated cases of AN, for genotyping of five microsatellite markers linked to the OTOF gene. The haplotype analysis showed compatibility with linkage in 11 families (including the four families with AN). Samples of the 11 probands from these families and from seven isolated cases of AN were selected for an exon-by-exon screening for mutations in the OTOF gene. Ten different pathogenic variants were detected, among which six are novel. Among the 52 pedigrees with autosomal recessive inheritance (including four familial cases of AN), mutations were identified in 4 (7.7%). Among the 11 probands with AN, seven had at least one pathogenic mutation in the OTOF gene. Mutations in the OTOF gene are frequent causes of AN in Brazil and our results confirm that they are spread worldwide.

Perioperative cortisol can predict hypothalamus-pituitary-adrenal status in clinically non-functioning pituitary adenomas.

BACKGROUND: Peri-operative steroids are administered routinely to patients with pituitary adenoma undergoing transsphenoidal adenomectomy (TSA). AIM: To evaluate hypothalamic-pituitary-adrenal (HPA) axis before and after programmed endoscopic TSA (E-TSA) in patients with clinically non-functioning pituitary macroadenoma (NFPA). DESIGN: Open prospective. SETTING: Tertiary referral hospitals. PATIENTS: Seventy-two consecutive patients (20-87 yr, 37 males). INTERVENTIONS: Adrenal steroid replacement therapy (ASRT) was given only in patients with hypocortisolism [08:00 h cortisol (F) <8 microg/dl]. MAIN OUTCOME MEASUREMENTS: After ETSA, achieving wide (>90%) selective resection of the adenoma in all, F and clinical picture were checked at day 2. The low-dose (1 microg) ACTH test (LDACTH) was performed at 6 weeks and repeated at 12 months. RESULTS: Hypocortisolism was present pre-operatively in 14 patients (19.4%), persisted post-operatively in all but one, and was detected de novo at the post-operative day 2 control in 6 (10.3%). In all but one the post-operative day 2 basal F and peak F during LDACTH test were concordant. No patient whose F was > 8 microg/dl was treated with ASRT or developed symptoms of adrenal failure during the follow-up (1-11 yr, median 5). CONCLUSIONS: HPA function is usually preserved in NFPA and is infrequently impaired after complete tumor removal by E-TSA. The 08:00 h. plasma cortisol evaluation before and 2 days after surgery, using as cut-off the value of 8 microg/dl, allows full evaluation of HPA status. Peri-operative steroid treatment should be given only in patients with hypocortisolism.

Somatostatin analogs and gallstones: a retrospective survey on a large series of acromegalic patients.

CONTEXT: Development of gallstones (GS) is reported during the use of somatostatin analogs (SA) that are at present the mainstay for the medical treatment of acromegaly. OBJECTIVE: To review the prevalence and clinical and biochemical correlates of GS in acromegalic patients. DESIGN AND SETTING: Retrospective survey on hospital records in acromegalic patients followed up in the last 20 yr in tertiary referral centers. PATIENTS: Four hundred and fifty-nine patients (272 females). MAIN OUTCOME MEASURES: According to SA use and GS occurrence, patients were divided in 4 groups: 1) treated with SA without GS (SA+GS-), 2) GS developed while on SA (SA+GS+), 3) GS without SA use (SA-GS+), 4) neither GS nor SA (SA-GS-). RESULTS: Patients were unevenly distributed in the 4 groups: 232, 125, 38, 64, respectively, pointing to a prevalence of GS in acromegaly of 8.3% at diagnosis with an additional 35% developing GS during SA. GS occurred after 3 months-18 yr (median 3 yr) of SA treatment, were diagnosed after symptoms in 17.6%, were associated to steatosis, ultrasound biliary dilation, and biochemical cholestasis, in 25.6%, 12.8%, and 4% of patients, respectively. Ursodehoxicolic acid was administered after GS occurrence, causing their dissolution in 39% of patients after 3-48 months (median 12). Cholecystectomy was performed in 16.8%of patients in group 2. At multivariate analysis obesity, dyslipidemia, and SA treatment were independent predictors of GS onset, whereas gender and age were not. CONCLUSIONS: GS are a frequent occurrence in acromegalic patients treated with SA, may occur at any time, but are seldom symptomatic or prompt acute surgery. Obesity and dyslipidemia appear to play a major role in the occurrence of GS in acromegalic patients on SA treatment.

The basal to total insulin ratio in outpatients with diabetes on basal-bolus regimen.

OBJECTIVE: To evaluate the basal/total ratio of daily insulin dose (b/T) in outpatients with diabetes type 1 (DM1) and type 2 (DM2) on basal-bolus regimen, by investigating whether there is a relationship with HbA1c and episodes of hypoglycemia. METHODS: Multicentric, observational, cross-sectional study in Italy. Adult DM1 (n = 476) and DM2 (n = 541) outpatients, with eGFR >30 mL/min/1.73 m2, on a basal-bolus regimen for at least six months, were recruited from 31 Italian Diabetes services between March and September 2016. Clinicaltrials.govID: NCT03489031. RESULTS: Total daily insulin dose was significantly higher in DM2 patients (52.3 ± 22.5 vs. 46 ± 20.9 U/day), but this difference disappeared when insulin doses were normalized for body weight. The b/T ratio was lower than 0.50 in both groups: 0.46 ± 0.14 in DM1 and 0.43 ± 0.15 in DM2 patients (p = 0.0011). The b/T was significantly higher in the patients taking metformin in both groups, and significantly different according to the type of basal insulin (Degludec, 0.48 in DM1 and 0.44 in DM2; Glargine, 0.44 in DM1 and 0.43 in DM2; Detemir, 0.45 in DM1 and 0.39 in DM2). The b/T ratio was not correlated in either group to HbA1c or incidence of hypoglycemia (<40 mg/dL, or requiring caregiver intervention, in the last three months). In the multivariate analysis, metformin use and age were independent predictors of the b/T ratio in both DM1 and DM2 patients, while the type of basal insulin was an independent predictor only in DM1. CONCLUSION: The b/T ratio was independent of glycemic control and incidence of hypoglycemia.

Correction to: The basal to total insulin ratio in outpatients with diabetes on basal-bolus regimen.

[This corrects the article DOI: 10.1007/s40200-018-0358-2.].

Anti-peptide reagent identifies a primary-structure-dependent, cross-reactive idiotype expressed on heavy and light chains from a murine monoclonal anti-CD4.

A synthetic peptide corresponding to the second complementarity determining region (CDR2) of the immunoglobulin (Ig) variable (V) region heavy (H) chain (CDR2VH) of anti-Leu3a, a murine monoclonal antibody specific for the human CD4 molecule, was used to elicit the production of specific rabbit anti-peptide antibodies. The rabbit anti-peptide antiserum was tested for reactivity against the immunizing peptide, anti-Leu3a, and a panel of mouse monoclonal anti-CD4. Only the immunizing peptide and anti-Leu3a were recognized by ELISA, whereas the H chains of anti-Leu3a and five other monoclonal anti-CD4 preparations were recognized by Western blot analysis. These data suggest that linear structures corresponding to the CDR2VH are not normally exposed on the surface of these monoclonal antibodies and become accessible only upon unfolding of the Ig molecule. In addition, Western blot analysis demonstrated that the anti-CDR2VH peptide antiserum was able to recognize the Ig light (L) chain of anti-Leu3a. This reactivity to both H and L chains from anti-Leu3a was ascribed to a homologous five amino acid sequence region shared by the two chains. The region of homology was associated with the third framework (FR3) of the L chain and was included as a portion of the sequence in the CDR2VH synthetic peptide. This observation was confirmed by the ability of the CDR2VH anti-peptide antiserum to bind the L chains of three mouse myeloma proteins that exhibited the five amino acid sequence region of homology within their respective FR3. Together, these data provide information on the structural basis of idiotypes shared by the H and L chains from the same antibody molecule and indicate that five amino acids might be sufficient to define a minimal continuous idiotypic determinant.

Anti-idiotypic antibodies of a predefined specificity generated against CDR3VH synthetic peptides define a private anti-CD4 idiotype.

A synthetic peptide corresponding to the third complementarity determining region (CDR) of the heavy chain (CDR3VH) of anti-Leu3a, a monoclonal anti-CD4 antibody which inhibits HIV gp120 binding to CD4, was used to elicit specific anti-peptide antibodies in rabbits. The anti-peptide antisera showed anti-idiotypic antibody (anti-Id) activity and recognized both the immunizing peptide and the intact cognate protein by ELISA. In addition, the antisera reacted with isolated heavy chains of anti-Leu3a by Western blot analysis. The lack of reactivity with a panel of monoclonal anti-CD4 antibodies suggested that the anti-peptide antisera recognize a private idiotype (Id) associated with the anti-Leu3a CDR3VH region. Further studies demonstrated the inability of the rabbit antisera to inhibit the binding of anti-Leu3a to the CD4 molecule. In addition, soluble recombinant CD4 was unable to inhibit the binding of the rabbit anti-peptide antisera to anti-Leu3a indicating that the CDR3VH region may not be involved in CD4 recognition. Anti-Id containing sera from mice, rabbits and nonhuman primates immunized with the intact anti-Leu3a molecule did not bind the CDR3VH synthetic peptide, suggesting that the corresponding region of anti-Leu3a may not represent an immunodominant idiotypic determinant in thes e species. These results suggest the potential use of synthetic peptides corresponding to immunoglobulin variable (V) region amino acid sequences in generating anti-Id reagents of a predefined specificity. In addition, V-region synthetic peptides may be useful in mapping the idiotopes recognized by an anti-Id response to the cognate molecule.

Primary hyperparathyroidism and Klinefelter's syndrome in a young man.

UNLABELLED: We report the association of primary hyperparathyroidism (PHPT) and Klinefelter's syndrome (KS) in a 22-year-old male complaining of worsening fatigue. PHPT was asymptomatic at the diagnosis, but the patient had worsening hypercalcemia and osteoporosis, and developed acute renal colic. He then underwent parathyroidectomy with resection of a single adenoma and normalization of calcium and parathyroid hormone levels. Clinical and therapeutic implications of this rare association are discussed. LEARNING POINTS: The coexistence of KS and PHPT is very uncommon.Patients with mild PHPT often have nonspecific symptoms that may be confused and superimposed with those of hypogonadism.KS patients, especially when young and already osteoporotic at diagnosis, should be screened for other causes of secondary osteoporosis, in particular PHPT.

Idiotypic cascades associated with the CD4-HIV gp120 interaction: principles for idiotype-based vaccines.

Idiotypes (Id) are antigenic determinants expressed on the variable (V) region of the immunoglobulin molecule. Id-bearing antibodies, or Ab-1, are produced upon stimulation with a given antigen. Ab-1 may elicit the production of anti-idiotypic antibodies (anti-Id) or Ab-2. The anti-Id also expresses Id determinants and may in turn elicit the production of anti-anti-Id or Ab-3. The production of Ab-1, Ab-2, and Ab-3 responses resulting from stimulation with the antigen is representative of components within an Id cascade. The existence of this Id cascade is the basis for the development of Id based strategies for controlling the immune response to infectious agents and tumors. In this review we will focus on several aspects regarding the Id cascades that may be operational during the immune response to the human immunodeficiency virus (HIV). In light of several studies which suggest the existence of Id-anti-Id interactions operating during the course of HIV infection, we will discuss the potential applications of Id based strategies in manipulating the immune response to HIV.

A comparison between octreotide-LAR and lanreotide-SR in the chronic treatment of acromegaly.

BACKGROUND: At present long-acting somatostatin analogs represent the first-line medical treatment of acromegaly. These drugs produce stable suppression of GH in most sensitive patients and IGF-I normalization in many; they also increase the compliance of acromegalic patients. The recent availability of octreotide (OC)-LAR, a somatostatin analog to be administered at 28-day intervals, has prompted us to compare, in the same group of patients, its effects and those of another somatostatin analog already available, lanreotide-SR (LSR, to be administered at 14-day intervals). PATIENTS: Twelve somatostatin analog-sensitive acromegalic patients with active disease were enrolled in a prospective open sequential study after giving their informed consent. After chronic treatment with LSR (6-24 months), the patients were changed to treatment with OC-LAR, without wash-out. LSR had been administered at individually tailored dosages (30 mg i.m. at 7-21-day intervals, median 10 days - every 7 days in seven patients, 10 days in two patients, 14 days in two patients and 21 days in one patient) according to GH and IGF-I responses. Disease stability was obtained, as shown by maximal GH/IGF-I suppression without any significant hormonal change between the last two control measurements. OC-LAR was administered i.m. at 28-day intervals six times at the dosage of 20 mg for the first three times and 10 or 30 mg for the last three times (according to individual GH/IGF-I responses). GH (mean of three, hourly samples) and IGF-I concentrations were evaluated on the same day as each administration of the drug, before its injection. RESULTS: GH and IGF-I values were significantly decreased by LSR treatment. GH decreased from 41.6 +/- 14.6 microg/l (mean +/- s.e.) to 7.2 +/- 1.5 microg/l (P < 0.02), whereas IGF-I values declined from 959 +/- 95 microg/l to 460 +/- 61 microg/l (P < 0.00001), expressed as absolute values, and from 287 +/- 30% to 137 +/- 19% expressed as percentage of the upper limit of normal range (% ULNR). At the end of the last cycle, OC-LAR treatment achieved a significant further suppression both in GH (to 5.1 +/- 1.1 microg/l, P < 0.05 compared with LSR) and in IGF-I concentrations (to 374 +/- 60 microg/l, P<0.05 compared with LSR, and to 112 +/- 19% as % ULNR). LSR decreased GH concentrations to less than 2.5 microg/l in one patient and normalized IGF-I concentrations in four patients. OC-LAR decreased GH concentrations to less than 2.5 microg/l in four patients and normalized or near-normalized IGF-I concentrations (i.e. to < 110% ULNR) in eight patients. CONCLUSIONS: These preliminary results show that the once-monthly OC-LAR administration schedule proved more efficacious than LSR given every 7-21 days, in a greater number of acromegalic patients.